A partial function of type PartialFunction[A, B] is a
unary function where the domain does not include all values of type
A. The function isDefinedAt allows to
test dynamically, if a value is in the domain of the function.

Variant of Iterable used to describe
collections with a finite number of elements.
Basically, this trait just adds size and toString to Iterable,
as most of the methods in Iterable already assume finite-ness.

A trait for representing equivalence relations. It is important to
distinguish between a type that can be compared for equality or
equivalence and a representation of equivalence on some type. This
trait is for representing the latter.
An equivalence
relation is a binary relation on a type. This relation is exposed as
the equiv method of the Equiv trait. This
relation must be:

Iterators are data structures that allow to iterate over a sequence
of elements. They have a hasNext method for checking
if there is a next element available, and a next method
which returns the next element and discards it from the iterator.

A trait for totally ordered data.
Note that since version 2006-07-24 this trait is no longer covariant in a.
It is important that the equals method for an instance of
Ordered[A] be consistent with the compare method. However,
due to limitations inherent in the type erasure semantics,
there is no reasonable way to provide a default implementation
of equality for instances of Ordered[A]. Therefore, if you need
to be able to use equality on an instance of Ordered[A] you must
provide it yourself either when inheiriting or instantiating.
It is important that the hashCode method for an instance of
Ordered[A] be consistent with the compare method. However,
it is not possible to provide a sensible default implementation.
Therefore, if you need to be able compute the hash of an
instance of Ordered[A] you must provide it yourself either when
inheiriting or instantiating.

A trait for representing total orderings. It is important to
distinguish between a type that has a total order and a representation
of total ordering on some type. This trait is for representing the
latter.
A total ordering
is a binary relation on a type T that is also an equivalence relation
and partial ordering on values of type T. This relation is exposed as
the compare method of the Ordering trait.
This relation must be:

reflexive: compare(x, x) == 0, for any x of
type T.

symmetry: compare(x, y) == z and compare(y, x) == w
then Math.signum(z) == -Math.signum(w), for any x and y of
type T and z and w of type Int.

A partial function of type PartialFunction[A, B] is a
unary function where the domain does not include all values of type
A. The function isDefinedAt allows to
test dynamically, if a value is in the domain of the function.

A trait for representing partial orderings. It is important to
distinguish between a type that has a partial order and a representation
of partial ordering on some type. This trait is for representing the latter.
A partial ordering
is a binary relation on a type T that is also an equivalence
relation on values of type T. This relation is exposed as
the lteq method of the PartialOrdering trait.
This relation must be:

Instances of responder are the building blocks of small programs
written in continuation passing style. By using responder classes
in for comprehensions, one can embed domain-specific languages in
Scala while giving the impression that programs in these DSLs are
written in direct style.

This class implements errors which are thrown whenever a
field is used before it has been initialized.
Such runtime checks are not emitted by default. See the
compiler documentation for knowing how to turn them on.
Note: This check requires the new initialization order,
planned for 2.8.0 and available under -Xexperimental.

The Console object implements functionality for
printing Scala values on the terminal. There are also functions
for reading specific values. Console also defines
constants for marking up text on ANSI terminals.